1. Field of the Invention
This invention relates to a novel buffering mechanism and a recording and/or reproducing apparatus. More particularly, it relates to a technique for increasing the contact area between a housed material or object and an elastic member interposed between the housed material or object and a housing member housing the material or object.
2. Description of Related Art
Up to now, it has been practiced to get an elastic member interposed between a housing member and a material or object, housed within the housing member, in order that the material or object housed within the housing member will be buffered against large vibrations or impacts transmitted via the housing member.
Among the elastic members, so far used extensively, there is a silicon-based buffering material 102 shown in FIG. 4 of Japanese Laying-Open Patent Publication 2002-334571, refered to Patent Publication 1 hereinafter, having substantially a cylindrical outer shape, and provided with a slit at a mid portion along the axial direction. A typical example of use of this sort of the elastic member is shown in FIGS. 22 and 23.
An elastic member 1 is of a substantially cylindrical outer shape and has a center through-hole 1a for support and with a slit 1b in its entire outer peripheral surface at a mid portion along the axial direction.
A supporting plate 3 of an L-shaped lateral side shape is secured to the housed material 2. The rim of a cut-out 3a formed in the support plate 3 is engaged in the slit 1b of the elastic member 1, whereby the elastic member 1 is supported via the support plate 3 by the housed material 2. In this manner, three or more elastic members, usually four elastic members 1, 1, . . . as in the buffering mechanism of the Patent Publication 1, are mounted to the housed material 2.
A shaft unit 4a is secured to a housing member 4 adapted for housing the material 2. The shaft unit 4a is inserted in the center through-hole 1a of the elastic member. A set screw 4b is threadedly mounted to the distal end of the shaft unit 4a to prevent the elastic member 1 from being detached from the shaft unit 4a. In this manner, the material 2 is housed within the housing member 4 through the elastic member 1.
In the buffering mechanism, shown in FIGS. 22 and 23, the vibrations or impacts, transmitted from outside the housing member 4, are buffered by the elastic member 1 and transmitted in this state to the housed material 2.
However, since the slit 1b has been formed in the elastic member and the elastic member is mounted by this slit 1b to the support plate 3 via this slit 1b, the degree of buffering is differential, in dependence upon the direction of transmission of the vibrations or impacts.
More specifically, the vibrations or impacts, applied from the direction of an arrow A in FIG. 22, may be sufficiently buffered by a sufficient thickness Ta of the elastic member 1 between the support plate 3 and the housing member 4, however, the vibrations or impacts, applied from the direction of an arrow B in FIG. 22, are buffered by a small thickness Tb of the elastic member 1 between the recessed end of the slit 1b of the elastic member land the inner peripheral surface of the center hole 1a thereof, so that the buffering action is not optimum. For this reason, the buffering mechanism of the Patent Publication 1, employing an elastic member mounted by the slit, as the elastic member 1, that is, the buffer material 102, has to use a two-step structure in which a storage device 10 as a housed material is first mounted to a metal fixture for mounting 12 via the buffer material 102 and in which the metal fixture for mounting 12 is mounted via a separate buffer material 101 to a metal fixture for external mounting 13 equivalent to the housing member 4.
With the cylindrically-shaped elastic member, having the slit in its outer peripheral surface, and supported relative to the housed material via this slit, the buffering action is directive, such that a marked difference in the buffering action is caused between the that acting in the axial direction of the cylindrical shape and that acting in the direction perpendicular thereto. Thus, if the similar degree of the buffering action is desirable for the direction indicated by arrow A and for the direction indicated by arrow B in FIG. 22, the structure for buffering is necessarily complicated, such as that shown in the Patent Publication 1, thus raising the cost. In addition, the buffering mechanism itself is large-sized due to the dual support structure for the material and to the presence of the different sort of the buffering material, with the consequence that the strong demand for a smaller size of the equipment cannot be met.
A buffering mechanism, shown in the patent publication 2, has also been proposed, in which a sufficient buffering action may be provided in two mutually perpendicular directions, such as the directions A and B in FIG. 22, with the use of a sole sort of the buffering material, without resorting to a dual structure.
That is, plural buffer structures (elastic members) 10a to 10d of an elastic material, in the form of collapsed sphere, are mounted at four inner corners of a material or object to be protected (object 12). The object 12 is housed within the housing member 14 so that the buffer structures 10a to 10d contact the housing member 14 at four inner corners (see FIGS. 1 to 3 of Japanese Laying-Open Patent Publication H11-37198, refered to Patent Publication 2 hereinafter). In this manner, the buffering structures 10a to 10d may perform satisfactory buffering actions in the mutually perpendicular directions of arrows C and D in FIG. 24, with the result that the object for protection 12 may be optimally buffered against the vibrations and impacts transmitted via the housing member 14.
Meanwhile, in the buffering mechanism, shown in the Patent Publication 2, the lateral surface sides of the buffer structures 10a to 10d are provided with cutouts 5, and the four corners of the object for protection 12 are fitted in these cut-outs 5, in order to mount the buffer structures 10a to 10d to the object for protection 12. Thus, the vibrations and impacts along the direction C are buffered mainly by the portion of each buffering structure 10a to 10d from the lower surface of the object for protection 12 to the lower end of the buffer structure 10a to 10d, that is, a thickness Tc. On the other hand, the vibrations and impacts along the direction D are buffered mainly by the portion of each buffering structure 10a to 10d from the lateral surface of the object for protection 12 to the outer lateral surface of each buffer structure, 10a to 10d, that is, a thickness Td.
As may be seen from FIGS. 2 and 3 of the Patent Publication 2 and from FIG. 24 hereof, Tc<Td. In this case, a problem is raised that the weight mass of the buffer structures 10a to 10d, carrying the weight of the object for protection 12 on application of vibrations or impacts, is evidently smaller than the vibrations or impacts acting in the direction of the arrow C. In particular, if the object for protection 12 is a hard disc drive, it is crucial that a head is able to buffer the vibrations or impacts efficaciously in the direction of the arrow C which is the direction in which the head is moved towards or away from the disc. If, in the structure of the Patent Publication 2, the effective thickness (Tc as aforementioned) of the buffer structures 10a to 10d, in the direction of the arrow C, is to be increased, the size of the buffer structures 10a to 10d in the direction of the arrow C, has to be increased, because the thickness of the hard disc drive cannot be reduced, thus increasing the thickness of the entire apparatus inclusive of the housing member 14.
Moreover, the buffer structures 10a to 10d are severely deformed in performing the buffering action. For example, in buffering the vibrations or impacts in the direction of the arrow C, a portion 6 of each buffer structure 10a to 10d lying directly below the object for protection 12 (shown netted in FIG. 24) is appreciably deformed, while the other portion, in particular the portion between the lateral surface of the object for protection 12 and the lateral surface of the housing member 14, is not likely to be deformed, so that the buffer structures 10a to 10d are severely deformed in shape. Thus, if simply the corners of the object for protection 12 are fitted in the cutouts 3a of the buffer structures 10a to 10d, the buffer structures 10a to 10d are highly likely to be detached from the object for protection 12. Although the buffer structures 10a to 10d and the object for protection 12 may be bonded together, the bonding step leads to onerous problems, such as storage and management of an adhesive or the management of the bonding step itself. Moreover, the bonding performance is degraded with lapse of time, while the buffer structures 10a to 10d are subjected to repeated deformation. In addition, there still persists the risk of the buffer structures 10a to 10d becoming detached from the object for protection 12.